The complementary role of lymphovascular invasion and perineural invasion in the TNM staging process of rectal cancer

Application of a combined clinical prediction model based on enhanced T1-weighted image(T1WI) full volume histogram in peripheral nerve invasion (PNI) and lymphatic vessel invasion (LVI) in rectal cancer

PURPOSE

This study aims to use a combined clinical prediction model based on enhanced T1-weighted image(T1WI) full volume histogram to predict preoperative peripheral nerve invasion (PNI) and lymphatic vessel invasion (LVI) in rectal cancer.

METHODS

We included a total of 68 PNI patients and 80 LVI patients who underwent surgical resection and pathological confirmation of rectal cancer. According to the PNI/LVI status, patients were divided into PNI positive group (n = 39), the PNI negative group (n = 29), LVI positive group (n = 48), and the LVI negative group (n = 32). External validation included a total of 42 patients with nerve and vascular invasion in patients with surgically resected and pathologically confirmed rectal cancer at another healthcare facility, with a PNI positive group (n = 32) and a PNI-negative group (n = 10) as well as an LVI positive group (n = 35) and LVI-negative group (n = 7). All patients underwent 3.0T magnetic resonance T1WI enhanced scanning. We use Firevoxel software to delineate the region of interest (ROI), extract histogram parameters, and perform univariate analysis, LASSO regression, and multivariate logistic regression analysis in sequence to screen for the best predictive factors. Then, we constructed a clinical prediction model and plotted it into a column chart for personalized prediction. Finally, we evaluate the performance and clinical practicality of the model based on the area under curve (AUC), calibration curve, and decision curve.

RESULTS

Multivariate logistic regression analysis found that variance and the 75th percentile were independent risk factors for PNI, while maximum and variance were independent risk factors for LVI. The clinical prediction model constructed based on the above factors has an AUC of 0.734 (95% CI: 0.591-0.878) for PNI in the training set and 0.731 (95% CI: 0.509-0.952) in the validation set; The training set AUC of LVI is 0.701 (95% CI: 0.561-0.841), and the validation set AUC is 0.685 (95% CI: 0.439-0.932). External validation showed an AUC of 0.722 (95% CI: 0.565-0.878) for PNI; and an AUC of 0.706 (95% CI: 0.481-0.931) for LVI.

CONCLUSIONS

This study indicates that the combination of enhanced T1WI full volume histogram and clinical prediction model can be used to predict the perineural and lymphovascular invasion status of rectal cancer before surgery, providing valuable reference information for clinical diagnosis.

Exploring treatment outcomes in Stage II-III rectal cancer patients undergoing neoadjuvant therapy at a tertiary care center in Pakistan: a comprehensive analysis of pathological outcomes

BACKGROUND

Rectal cancer treatment has transformed in recent years, with neoadjuvant treatment (NT) and total neoadjuvant treatment (TNT) aiming to enhance pathological responses. This pioneering study in our country delves into rectal cancer management, offering crucial insights by examining pathological outcomes in patients treated with the NT and TNT approach, shaping the evolving landscape.

METHODS

In this retrospective-cohort study spanning January 2017 to December 2022 at a tertiary care hospital in Pakistan, ethical approval was obtained to examine outcomes of two treatments. Patients were divided into TNT (chemoradiation and pre-surgery 5 FU-based chemotherapy) and NT (chemoradiation, surgery, and subsequent 5 FU-based chemotherapy). The primary end-point was response rates-no response, pathological complete response (pCR), near complete response (near CR), and partial response (PR). The Chi-Square Test for Independence assessed the association between treatment response and type (TNT or NT). Data analysis used STATA MP 64; significance was set at p < 0.05 for all two-tailed tests.

RESULTS

We analyzed 77 patients, 60 underwent standard neoadjuvant chemoradiation, and 17 followed the total neoadjuvant approach. Predominantly male, most were > 65 with ECOG 0-1. The TNT group showed higher response rates (76% vs 62%, p = 0.039), with 40.38% achieving pCR. In the overall population, pCR and near-CR were similar (27.2% vs 26%), while PR were 14%. Treatment characteristics correlated significantly with chemotherapy type, concurrent chemoradiation, LVI, PNI, and T, N, M staging (p < 0.05). Median overall survival was not reached, and mean survival was 89.1 months (CI: 95.0 to 83.3). Side effects varied, with notable differences in neuropathy, diarrhea, oral mucositis, and thrombocytopenia between NT and TNT groups.

CONCLUSION

Our study adds to evidence favoring neoadjuvant approaches in managing rectal cancer in pakistan. Demonstrating a favorable pcr rate, ongoing research with extended follow-up is essential, given the dynamic landscape of rectal cancer treatment for improved patient outcomes.

The Incidence of Lymphovascular and Perineural Invasion and their Impact on Survival in Patients with Rectal Cancer

Aim: Lymphovascular Invasion (LVI) and Perineural Invasion (PNI) represent undesirable but still realistic pathological features of rectal cancer, associated with poor prognosis and worse survival. The aim of this study is to assess the incidence of LVI and PNI in patients treated for rectal cancer and the impact of LVI and PNI on patient survival. Material and Methods: This retrospective single center observational study, conducted in the period of 2016-2019, includes patients with rectal cancer treated with/without long-course neoadjuvant chemoradiotherapy (nCRT). Data collection encompassed demographics, tumor characteristics, type of surgery (abdominal perineal rectal resection - APR and low anterior rectal resection - LAR), and LVI/PNI presence. Survival during follow-up was estimated and compared for patients with/without LVI and PNI involvement. Results: A total number of 234 patients (77 females and 157 males) with mean age of 61.3 enrolled in the study. Neoadjuvant CRT was conducted in 170 patients. APR procedure was performed in 67 of them and LAR in 167. LVI presence was noted in 55 (24.4%) and PNI in 77 (34.2%) patients. Mean survival during follow-up was 42.07 months. The use of nCRT influenced on survival (p < 0.033). Patients treated with LAR had better survival outcomes (p = 0.001). Presence of LVI and PNI was associated with a worse prognosis (p < 0.001). Conclusion: PNI was more frequent than the LVI in this study. Patients with nCRT conduction had better overall survival. LVI and PNI presence was associated with poor prognosis in terms of overall survival in patients with rectal cancer.

Risk-factors for locally advanced rectal cancer relapse after neoadjuvant chemoradiotherapy: A single center experience

The overall prognosis of locally advanced rectal cancer (LARC) remains unsatisfactory due to a high incidence of disease relapse. The present understanding of the factors that determine the likelihood of recurrence is limited or ineffective. We aimed to identify the main risk factors influencing tumor relapse in LARC patients after neoadjuvant chemoradiotherapy (nCRT) and surgical treatment in a single center in Republika Srpska. Patients with stage II or stage III who received nCRT before surgery for primary rectal cancer at the Oncology Clinic, University Clinical Center of Republika Srpska from January 2017 and December 2022 were included in the study. We collected patient demographics, clinical stage and characteristics, neoadjuvant therapy, and surgical methods, along with the pathological response after treatment completion, and analyzed them to identify the risk factors for tumor relapse. Out of 109 patients diagnosed with LARC, 34 (31,2%) had tumor relapse. The median time to relapse was 54 months. Participants with clinical T4 stage had a significantly shorter relapse time compared to the patients with clinical T2/3 stage. Subjects with positive lymph nodes removed, perivascular and perineural invasion, intraoperative perforation and patients without ypN stage improvement had significantly shorter time to relapse. Subjects with T4 stage had more than 4 times higher risk of relapse than patients with clinical T2/3 stage. Higher clinical T stage was an essential risk factor for tumor relapse in LARC patients after nCRT and surgical treatment. Comprehensive understanding and identification of the risk factors for tumor relapse in LARC patients are crucial for improving their long-term outcomes.